A practical and highly sensitive C3N4-TYR fluorescent probe for convenient detection of dopamine.

The C3N4-tyrosinase (TYR) hybrid is a highly accurate, sensitive and simple fluorescent probe for the detection of dopamine (DOPA). Under optimized conditions, the relative fluorescence intensity of C3N4-TYR is proportional to the DOPA concentration in the range from 1 × 10(-3) to 3 × 10(-8) mol L(-1) with a correlation coefficient of 0.995. In the present system, the detection limit achieved is as low as 3 × 10(-8) mol L(-1). Notably, these quantitative detection results for clinical samples are comparable to those of high performance liquid chromatography. Moreover, the enzyme-encapsulated C3N4 sensing arrays on both glass slide and test paper were evaluated, which revealed sensitive detection and excellent stability. The results reported here provide a new approach for the design of a multifunctional nanosensor for the detection of bio-molecules.